The best theologians, past and present, have been divided on the question of whether Jesus could have sinned. I believe that since Jesus was fully human, it was possible for him to sin. Obviously, the divine nature cannot sin. But if Christ's divine nature prevented him from sinning, in what sense did he obey the law of God as the second Adam? At his birth, Jesus' human nature was exactly the same as Adam's before the fall, with respect to his moral capabilities. Jesus had what Augustine called the posse peccare and the posse non peccare, that is, the ability to sin and the ability not to sin. Adam sinned; Jesus did not. Satan did everything in his power to corrupt Jesus and tempt him to sin. That would have been an exercise in futility had he been trying to tempt a divine person to sin. Satan was not trying to get God to sin. He was trying to get the human nature of Christ to sin, so that he would not be qualified to be the Savior.
I think it is wrong to believe that Christ’s divine nature made it impossible for his human nature to sin. —R.C. Sproul
At the same time, Christ was uniquely sanctified and ministered to by the Holy Spirit. In order to sin, a person must have a desire for sin. But Jesus' human nature throughout his life was marked by a zeal for righteousness. "My food is to do the will of Him who sent Me" (John 4:34), he said. As long as Jesus had no desire to sin, he would not sin. I may be wrong, but I think it is wrong to believe that Christ's divine nature made it impossible for his human nature to sin. If that were the case, the temptation, the tests, and his assuming of the responsibility of the first Adam would have all been charades. This position protects the integrity of the authenticity of the human nature because it was the human nature that carried out the mission of the second Adam on our behalf. It was the human nature uniquely anointed beyond measure by the Holy Spirit.
Excerpt from R.C. Sproul's, Truths We Confess